A114744 a(1) = 1, a(2) = 2, a(n+1) = least strictly positive number of the form k*a(n-1) - a(n), not included earlier.

1, 2, 3, 5, 4, 6, 10, 8, 12, 20, 16, 24, 40, 32, 48, 80, 64, 96, 160, 128, 192, 320, 256, 384, 640, 512, 768, 1280, 1024, 1536, 2560, 2048, 3072, 5120, 4096, 6144, 10240, 8192, 12288, 20480, 16384, 24576, 40960, 32768, 49152, 81920, 65536, 98304, 163840, 131072

Offset

1,2

Comments

a(5) onwards terms match with that of A114743.

Links

Table of n, a(n) for n=1..50.

Formula

a(3*n+5) = 2*a(3*n+2) = 2^(n+2); a(3*n+6) = 2*a(3*n+3) = 3*2^(n+1); a(3*n+7) = 2*a(3*n+4) = 5*2^n.

Example

a(28) - a(29) = 256, therefore a(30) = 7*256 = 1536. - Georg Fischer, Apr 18 2025

Maple

A114744 := proc(nmax) local a, k, nxt; a := [1, 2] ; while nops(a) < nmax do k := 1; nxt := k*op(-2, a)-op(-1, a) ; while nxt in a or nxt <=0 do k := k+1 ; nxt := k*op(-2, a)-op(-1, a) ; od ; a := [op(a), nxt] ; od ; a ; end: A114744(80) ; # R. J. Mathar, May 10 2007

Crossrefs

Cf. A114743.

Sequence in context: A365390 A376686 A359557 * A352715 A096114 A344169

Adjacent sequences: A114741 A114742 A114743 * A114745 A114746 A114747

Keyword

nonn

Author

Amarnath Murthy, Nov 15 2005

Extensions

More terms from R. J. Mathar, May 10 2007

a(30) = 1536 inserted by Georg Fischer, Apr 18 2025

a(49)-a(50) corrected by Alois P. Heinz, Apr 18 2025

Status

approved